The Clausing 5400 was based on the same flame-hardened bed as the more expensive 6300 Model, but used less sophisticated ancillary equipment; the 5400 was originally the Model 100 and the 6300 the Model 200; check here for their early history.
As standard the headstock was supplied with a hardened spindle, threaded 21/4" x 8 tpi, with the option of an L00 fitting at extra cost. A conventional tumble reverse mechanism was fitted to the changewheel drive and the gearbox was of the traditional Norton Quick-change pattern, with a single tumbler and open base, as fitted, for example, to early South Bend lathes.
The 5400 was available with either a conventional V-belt drive countershaft unit mounted within the stand, or a variable-speed drive identical in layout to that on the 6300. Unlike other contemporary Clausing lathes, the headstock drive pulley was placed between the bearings, not on the left-hand end of the spindle.
The ordinary step-drive system gave ten spindle speeds between 35 and 1600 rpm or, fitted with a two-speed motor, 20 speeds from 17 to 1600 rpm, a rather better range than that available from the 6300. The variable-speed drive unit spanned 35 to 1600 rpm, again superior to the 6300 with its 43 to 1300 rpm range.
The lathe illustrated above is fitted with the optional clutch and brake unit, the operating handle for which can be seen protruding from the stand under the screwcutting gearbox.